1. Field of the Invention
The present disclosure relates to an information processing system, a client device and a method of control.
2. Description of the Related Art
A system has been proposed that enables use of various services on the Internet from a terminal of an intranet provided in a corporate environment. This system generally includes installation of a firewall on the internet/intranet boundary. The firewall allows connection from the intranet to the Internet, but is configured to refuse connection from the Internet to the intranet. In this manner, access from a terminal on the Internet into the intranet is limited. The above configuration is also premised on the fact that a conventional communication system using the WEB generally includes performance of an information acquisition request from a client to a server by PULL-type communication in which the server responds by transmitting the information.
However, in recent years, technical developments in PUSH-type communication have increased in which information is sent from the server to the client. An example of a PUSH-type communication technology is Comet or WebSocket. If an HTTP request is sent by a client to a server in Comet, the server retains the request without immediately responding. Thereafter, when information is produced to be sent from the server to the client, the information is sent as a response to the retained request.
WebSocket is a technology for bidirectional communication prepared by W3C or IETF which is the standardization body for the Internet. Establishment and maintenance of a TCP connection, rather than an HTTP connection, does not require mapping onto a HTTP protocol such as when using Comet, and thereby enables communication at a free timing from either the client or the server.
In this manner, in the context of a PUSH-type communication technology, information can be sent by use of a server connection even in an environment provided with a firewall by establishing and maintaining a connection from a client in an intranet.
Consequently, in recent years, a printing system has been proposed that uses PUSH-type communication. A PUSH-type printing system establishes a connection of a client device (printer) in an intranet with a server apparatus (print server) and constantly maintains that connection. In this manner, the print server can issue a request (print job execution request) when the print server is the starting point, and communicate that request at an arbitrary timing through a firewall to a printer. Japanese Patent Application Laid-Open No. 2008-140275 discloses a communication system configured so that an external host in an external network can transmit communication path maintenance data to an internal host with which access by the external host is restricted by a firewall for the maintenance of a communication path to the internal host.
For the promotion of continuous system development, a PUSH-type communication system using WebSocket has added a WebSocket connection in response to the addition of an application. That is to say, rather than for each printer, a WebSocket connection is required for each application that is installed on a printer.
When a WebSocket connection is provided for each application, the processing load for management of a constant connection for the number of applications by the print server is increased as the number of applications increases. Consequently, print server operations may become unstable or suitable processing operations may no longer be enabled. Furthermore, in a PUSH-type communication system using WebSocket, when a printer is started up, the printer must extend the WebSocket connections corresponding to the number of preinstalled applications. Therefore, the WebSocket connections that correspond to the applications that are not used for execution of a request issued by the print server are consequently an unnecessary resource.